Feeding mechanism for sewing-machines.



J. 0. HUFFMANISL J. LAUPFER. FBBDING MEGHNISM FOR SEWING MAGHINESV.APPLICATION FILED APR. 25, 1910.

Patented May 7, 1912.

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Inventors 555%@ y I l J. o. HUPPMAN & E. J. LAUPPER. I'EEDING MEGHANISMFOR 'SEWING MACHINES.A APPLICATION FILED APR.25, 1910.

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"UNTTED sTATEs PATENT onnicn.

JOHN O. HUFFMAN AND EMIL J. LAUFFER, OF CLEVELAND, OHIO, ASSIGNORS TOTHE I'HITE SEWING MACHINE COMPANY, OF CLEVELAND, OHIO, A CORPORATION OFOHIO.

FEEDING MECHANISM FOR SEWING-MACHINES.

Specication of Letters Patent.

Application filed April 25, 1910. Serial No. 557,364.

To all whom t may concern Be it known that we, JOHN O. HUFFMAN and EMILJ. LAUFTER, citizens of the United States, and residents of Cleveland,in the county of Cuyahoga and State of Ohio, have invented a certain newand useful Improvement in Feeding Mechanism for Sewing- Machines, ofwhich the following is' a full, clear, and exact description.

This invention relates to improvements in feeding mechanism for sewingmachines.

The object is to provide such mechanism in a form which may be quicklyadjusted to vary the length of the stitch or feed, and

which will work with very little frictionv and with equal freedom in allof its various adjusted positions.

In the drawing, Figure 1 is a bottom view of a sewing machine head towhich the presentinvention is applied. Fig. 2 is a sectional view online 2-2 of Fig. 1. Fig. 3 is a sectional view on line 3-3 of Fig. l;and Fig. 4 is an end view from the right end of Fig. 1.

Referring to the parts by letters, A represents the base or bed plate ofa sewing machine head.

B represents a driven rotatable shaft mounted in suitable bearings andlying beneath the bed plate. It is of no consequence to the presentinvention as to what mechanism is employed to rotate this shaft, and noeffort has been made to show any particular mechanism for doing this,because such mechanism in a variety of forms is well known in the art.

G represents the feed-bar rock shaft which is mounted in suitablebearings on the under side of the bed plate, and is parallel to theshaft B.

Anarm g is fixed to the shaft B and extends upward vertically a shortdistance; and it is pivoted to the rear end of the feed bar E. This baris forked at its front end and embraces a suitably shaped cam F fixed tothe shaft A. A flange f fixed also to the shaft B, and the left end ofthe bracket a, which is fixed to the bed, lie on either side of the cam;and the forks of the feed bar lie between these surfaces, whereby it isguided in its movements. At the other end of the shaft B another cam,which is shown in dotted lines in Fig. t, and is indicated by R, issecured. A forked arm P embraces this cam, and is itself fixed toa rockshaft C mounted in suitable bearings which project down from the bedplate. An arm K xed to the rock shaft C extends radially and nearlyvertically therefrom; and in its end face is a guide-way k which extendsfrom the axis of the shaft C upward. In this guide-way a block J ismovable. A link H is pivoted to this block, and is likewise pivoted toan upwardly extended arm g fixed to the rock shaft G.

It is quite evident from the foregoing statement that as theshaft Brotates the cam R will rock the rock-shaft C, and thereby the arm K willbe rocked. The rocking motion of this arm will be transmitted throughlink H to the shaft Gr, and the rocking motion of the shaft Gr will betransmitted through the arm g to the feed bar E, thereby imparting to ita reciprocatoryv forward and backward movement. While this movement isgoing on, the feed bar is likewise being moved up and-down at properintervals by the action of cam F upon said feed bar.

The block J has connected with it by the same pivot screw I whichYconnects a link II with it, a short link M, the lower end of which ispivotally connected with an arm a fixed to a rock shaft N, to which alsoan operating arm a is fixed.

In order to vary the length of the forward and backward movement of thefeed bar (which is to vary the length of t-he stitch) the operator takeshold of the arm n and swings it forward or backward, said arm projectingup through a slot in the bed plate to a convenient place for itsoperation. By the rocking of the shaft N the block J will be movedtoward or away from the axis of the shaft C. The farther it is away fromit the greater will be the arc through which the shaft Gr will berocked, and consequently the greater will be the forward and backwardmovement of the feed bar. By bringing the block J so far down that theaxis of the shaft C will be coincident with the axis of the pvot screwwhich connect-s the link H and block J, there will be no rockingmovement whatever of the shaft G, and consequently no backward movementof the feed bar.

Having described our invention, we plate and having an operating armwhich claim: extends upward through a slot in `the bed The combinationof a rotatable shaft carrying two cams, a rock shaft having two armsfixed to it, a feed bar pivoted to one of said arms and extendingforward therefrom, said feed bar being forked to embrace one of the camsupon said rotatable shaft, a rock shaft C, a forked arm fixed theretoand embracing the other cam on the rotatable shaft, an arm K fixed tosaid rock shaft and having a guide-way which extends across the axis ofsaid shaft, a block movable in said guide-way, a link connecting saidblock and the other arm of the rock shaft, a rocker pivoted to a fixturebelow the bed plate and has also a substantially horizontal arm, and alink pivotally connected with the last named arm and extending upwardtherefrom and being pivoted at its upper end to said block.

ln testimony whereof we hereunto aiix our signatures in the presence oftwo witnesses.

JOHN O. HUFFMAN. EMIL J. LAUFFER.

Witnesses:

H. R. SULLIVAN, E. L. THURs'roN.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

